It is known to use intervertebral implants to restore the anatomic intervertebral space between two vertebrae. However, the existing implants are not completely satisfactory, in particular as regards the treatment of cervical vertebrae by anterior approach route, either because they do not restore perfectly the intervertebral space, or because they form obstacles to the movements of the vertebrae, or because they induce risks of insertion in the vertebral plates, or because they are difficult to implant, or because their durability or the anchoring thereof is questionable.
The document U.S. Pat. No. 5,749,916 describes a fusion cage slit laterally to enable the application of stresses on a graft contained in the wedge and/or for restoring anatomic mobility between two vertebrae.
This implant is not intended for treating cervical vertebrae by anterior approach route, and the implant according to the invention does not comprise any lateral slot.
There is also provided, by the document WO 01/62190, an intervertebral implant comprising a U-shaped body seen laterally, i.e. showing two lateral branches resting against the vertebral plates and a posterior “wall”. This body is deformable elastically for the insertion thereof between the vertebrae to be treated and to enable restoration of the mobility of the vertebrae, and forms protruding tabs for the attachment thereof to the vertebrae.
This implant is estimated as not satisfactory from the point of view of the restoration of an intervertebral space with mobility of the vertebrae. Indeed, the screw attachment of this implant is considered as not suitable for such a restoration, taking into account the risks induced of a vertebral fusion by growth of the bony cells, which may result in immobilisation of the vertebrae. Moreover, the resistance of this implant to the repeated stresses transmitted by these vertebrae is considered as questionable.
The purpose of the present invention is to remedy these shortcomings.